1. Field of the Invention
The present invention relates to a liquid crystal display having display elements formed in vicinity of cross points of signal lines and scanning lines on an insulation substrate.
2. Related Art
When a voltage is always applied to in the same direction with respect to liquid crystal, baking of liquid crystal occurs. Ordinarily, polarity reversal drive is performed in a liquid crystal display. In the polarity reversal drive, polarity of the applied voltage is switched at a constant period. There are a dot reversal drive for switching polarity for each pixel, a line reversal drive for switching polarity for each line, a frame reversal drive for switching polarity for each frame and the like.
In the case of performing the polarity reversal drive, voltage polarities of a signal line voltage and an auxiliary capacitor power supply line connected to an auxiliary capacitor have to be periodically changed. Because of this, there is a case of providing a plurality of reference power supplies for setting a voltage of the auxiliary capacitor power supply line (see Japanese Patent Publication Laid-Open No. 255851/2001).
However, when the power supply is on, the reference voltage that the auxiliary capacitor power supply line is connected becomes unstable. As a result, the voltage applied to the liquid crystal layer changes for each auxiliary capacitor power supply line, and there is a problem in which an undesirable bright line in a horizontal direction emerges.